Inside filter for aquariums

ABSTRACT

A bottom aquarium filter for an aquarium tank including a substantially cylindrical container having an inwardly directed concave forward wall. A grill wall removably coupled onto the concave forward wall and defining therewith an inlet chamber. A removable L-shaped insert member includes a substantially circular perforated platform wall and an upstanding convex partition wall. The platform wall spacedly sits on the bottom of the container and defines with the container a filtration chamber above the platform and a clear water chamber beneath the platform. The partition wall mates in opposition against a rear peripheral section of the circular wall of the container and defines therewith an air lift chamber. A removable cover mounts onto the container and includes a mouth aligned with the air lift chamber. The cover serves to retain all of the members in unitary assembly. An air tube fits into a spout projecting from the rear peripheral wall and extends into the air lift chamber terminating in an air diffuser which sits in a depressed compartment beneath the base wall of the container. The air tube can serve as a handle for lifting the filter assembly. The assembly can be easily separated for cleaning without the difficulty in reaching any portion of pre-formed compartments.

BACKGROUND OF THE INVENTION

This invention relates to aquarium filters, and more particularly toaquarium filters of the type which can be placed at the bottom of theaquarium for filtration and aeration of contaminated water contained inthe aquarium.

A common type of aquarium filter is generally referred to as the bottomaquarium filter. Such type of filters are positioned at the bottom ofthe tank, normally above the gravel bed. Such typical filters are shownin U.S. Pat. Nos. 2,782,161; 3,477,580; 3,630,367 and 4,186,093. Thefilters described in these, as well as various other bottom aquariumfilters, all have various chambers defined for specified purposes.Specifically, there is typically defined a receiving chamber forreceiving the contaminated water from the aquarium filter and passing itthrough filtration material. The water is then collected in a clearwater chamber which is in flow communication within an air lift tube. Asupply of air is provided to the bottom of the air lift tube and as theair drifts upwardly in the air lift tube it draws the water from theclear water chamber into the air lift tube to pass upwardly along withthe air and then back into the aquarium tank in an aerated and filteredcondition. The construction of the various prior art filters includedwell defined individually constructed compartments, each of whichrespectively served as one of the aforementioned chambers. Whenassembled, these compartments were joined to form the aquarium filter.In order to clean the filter, the various compartments had to beseparated and individually cleaned. The cleaning of individualcompartments caused difficulty since narrow brushes were often requiredto fit into crevices and corners of the various compartments and therebyinadequate cleaning often occurred.

An additional problem with the aforementioned prior art filters was thedifficulty in manipulating these filters. Once assembled, the filtermust be lowered into the aquarium tank and suitably positioned. In manycases, lowering the filter will cause it to be improperly situated inthe tank and further manipulation of the filter assembly is required inorder to properly position it at an appropriate location. Withoutexternally available handles the aquarium owner's hands must be placedwithin the tank to reach the filter in order to properly position it.Similarly, insertion of the hands into the tank is required in order toextract the filter for cleaning. Such insertion of the hands oftendisturb the fish environment and may even contaminate the aquarium watercausing damage to the various fish and plant life within the aquariumtank.

With most of the previous aquarium filters, the particular shape of theaquarium filter was rectangular so as to permit positioning of theaquarium filter in a corner of the aquarium tank. However, in doing so,narrow spaces were formed between the planar walls of the aquariumfilter and the correspondingly planar walls of the filter tank. Suchnarrow spaces often provided insufficient room for the fish to swimtherethrough and often fish could get caught and trapped between thewalls of a square, rectangular or triangular shaped filter having flatsides with these sides confronting the aquarium tank walls.

Another construction problem with the prior art filters concerns theappropriate supply of air into the air lift chamber. Typically, a tubeis inserted into the air lift chamber with an air diffuser or air stone,or the like, depending from the distal end of the tube. The air diffuseris usually placed at the lower portion of the air lift chamber and airsupplied through the tubing is diffused through the air diffuser. Sincethe clear water chamber is usually adjacent or beneath the air liftchamber, the air passing from the air diffuser and flowing upwardly doesnot adequately pass by the clear water chamber itself and accordinglyinsufficient suction is provided by the air flow. Furthermore, the airflow does not have an opportunity to pass through the entire height ofthe air lift chamber since the air diffuser itself occupies aconsiderable portion of the height of the air lift chamber and airleaving from all parts of the air diffuser only has a portion of theheight of the air lift chamber to travel through. Such short travel pathprovides insufficient aeration of the clear water passing back into theaquarium tank and also provides insufficient suction for adequate flowof water through the filter.

Accordingly, while the prior art bottom aquarium filters have beenutilized quite successfully, further improvement is warranted in orderto alleviate the aforementioned problems.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide anaquarium filter which avoids the aforementioned problems of prior artdevices.

Another object of the present invention is to provide a bottom aquariumfilter in which the individual filter chambers are compositely formed ofseparating walls so as to permit easy cleaning of all parts of theaquarium filter.

Yet another object of the present invention is to provide a bottomaquarium filter having an assembly of parts which are compositely heldtogether in an assembled condition by means of a tightly fitting cover.

Another object of the present invention is to provide a bottom aquariumfilter having an air tube with a depending air diffuser which extendsinto the air lift chamber, and for retaining the air diffuser secured inthe chamber so that the air lift tube can serve as a handle forinsertion, removal, or manipulation of the aquarium filter.

Yet another object of the present invention is to provide a bottomaquarium filter which is substantially cylindrical in shape, in order toavoid the trapping of fish between the walls of the filter and theaquarium tank.

Still a further object of the present invention is to provide a bottomaquarium filter where the air diffuser is retained, at the base of theair lift chamber so as to provide maximum lift of the water, therebyadding to the force of the flow of water through the filter and improvethe aeration of the water returning to the aquarium.

A further object of the present invention is to provide a bottomaquarium filter having an elliptically shaped receiving chamber and airlift chamber, permitting a greater filtration compartment for filteringof the contaminated water.

Another object of the present invention is to provide a bottom aquariumfilter having an integrally formed pedestal portion for positioningbeneath the gravel of the aquarium tank, whereby the pedestal portioncannot fall off as the filter is lifted or manipulated.

Yet another object of the present invention is to provide a bottomfilter having a receiving chamber and an air lift chamber respectivelydefined by the composite mating of opposing wall members, and includinga cover which tightly presses the wall members together so as to avoidleakage from the various compositely formed chambers.

Briefly, in accordance with the present invention, there is provided anaquarium filter for positioning at the bottom of an aquarium tank. Thefilter includes a container with a forward wall. A grill wall isremovably coupled in opposition to the forward wall to define therewiththe inlet receiving chamber for receiving contaminated water from theaquarium tank. An inside member is provided which includes a perforatedplatform wall integrally connected with an upstanding partition wall.The platform wall is spacedly seated onto the bottom of the containerand defines with the bottom of the container a clear water chamber. Theportion of the container above the platform defines a filtrationchamber. The partition wall mates in opposition against a rear sectionof the container wall and defines therewith an airlift chamber. Aremovable cover is mounted onto the container and includes a mouth whichis aligned with the air lift chamber. The cover locks onto the containerand retains the various sections thereof in a tight assembled condition.

Contaminated water from the inlet chamber can flow over the forward wallof the container and into the filtration chamber. The water is thendecontaminated through filter material retained within the filtrationchamber and then passes through the perforated platform to the clearwater chamber. The water can then egress through the air lift chamberand out of the mouth provided in the cover. In an embodiment of theinvention the filter container is substantially cylindrical in shapewith the forward wall being inwardly directed and concavely shaped. Thegrill wall is removable and has a slight convex shape defining with theforward wall an elliptically shaped receiving chamber. The inside memberis L-shaped and removable with its platform being circular. Thepartition wall is convex to define with the rear peripheral circularwall of the container an elliptically shaped air lift chamber.

In an embodiment of the invention, a spout is provided in the rear wallof the cylindrical compartment in flow communication with the air liftchamber. A tubing passes downward through the spout and into the airlift chamber with an air diffuser depending from the distal end of thetubing. A shoulder member extending into the air lift chamber maintainsthe air diffuser positioned at the base of the air lift chamber. In thismanner, the air diffuser is securely retained in place with the covermounted on the container and the tubing can be used as a handle forsecurely lifting, manipulating, and inserting the aquarium filterappropriately in the aquarium tank.

In an embodiment of the invention, a depressed compartment is formed inthe base wall of the container and a raised instep is formed between thejunction of the platform and the upstanding wall partition. Thedepressed compartment in conjunction with the mating raised instepdefines a receiving compartment for the air diffuser and positions theair diffuser at a level so that at least a portion of it is beneath theclear water chamber. In this manner, the air supplied through the airdiffuser has a greater flow path providing increased lift for the water,greater suction, and improved aeration of the water returning to theaquarium tank.

The shape of the air diffuser receiving compartment can be formed with asloped forward end in order to direct the air from the air diffuser intothe air lift chamber to thereby further improve the suction and flow ofthe water through the filter.

A retaining member can depend from the cover to retain the filtrationmaterial and maintain a spaced flow chamber between it and the cover.The arrangement permits flow of contaminated water from the receivingchamber to the filtration chamber.

The aforementioned objects, features and advantages of the inventionwill, in part, be pointed out with particularity and will, in part,become obvious from the following more detailed description of theinvention, taken in conjunction with the accompanying drawings, whichform an integral part thereof.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is a perspective exploded view of the various parts of the filterassembly in accordance with the present invention;

FIG. 2 is a perspective view of the assembled aquarium filter inaccordance with the present invention;

FIG. 3 is a cross sectional view taken along lines 3--3 of FIG. 2;

FIG. 4 is a front elevational view, partially in section, of theaquarium filter in accordance with the present invention, and

FIG. 5 is a cross sectional view taken along lines 5--5 of FIG. 4.

In the various figures of the drawing, like reference charactersdesignate like parts.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, the bottom aquarium filter showngenerally at 10 includes a substantially cylindrical housing container12, an L-shaped removable insert member 14, a forward grill wall 16, acover member 18, an air lift tubing member 20, and a retaining member22.

The container 12 includes a substantially cylindrical peripheral outerwall 24, terminating in a substantially flat upper edge 26. A lower basewall 28 closes off the bottom of the container and interconnects with anarrow neck portion 30 coupling to a flat pedestal 32. The neck portionincludes tapered forward and rear walls 34, 36 with the forward wall 34being substantially steeper than the rear wall 36. The upper end of thecontainer 12 is open.

At the forward portion of the cylindrical container, the cylindricalouter wall is spaced apart by a gap which is closed off by an inwardlyoriented concave wall 38. The peripheral outer wall extends partiallyinto the gap on either side of the concave wall 38 to form the side edgewalls 40, 42. As best seen in FIGS. 1 and 5, wall 38 is upwardly taperedso as to provide a wider mouth at the top. A notched shoulder 44, 46 isprovided at the upper edge of the walls 40, 42.

An outwardly projecting spout 48 is formed at the upper edge of the rearportion of the peripheral outer wall 24. The spout includes a rearwardlydirected part 50 angularly directed from the rear portion of theperipheral wall and terminating in the upper edge 52 defining a mouthportion.

An opposing pair of outwardly projecting, upwardly flared receivingchannels 54, 56 are positioned on either side of the spout 48. Upwardlyprojecting tabs 58, 60 are opposingly positioned on lateral sides of thecylindrical container 12 orthogonally positioned with respect to thespout and forward wall axis. The locking tabs 58, 60 have respectiveoutwardly extending lips 62, 64. The tabs 58, 60 engage into sockets inthe cover member 18, as will hereinafter be described. Thumb gripportions could be formed into the outer periphery of the container wallsbeneath the locking tabs 58, 60 so as to provide finger grips forcompression of the opposing cylindrical side walls to release thelocking tabs from the sockets in the cover member.

The grill member 16 includes a convex outer wall 66 having a grill 68formed therein, the grill 68 is formed of a plurality of slats 70separated by spaces 72. The slats 70 have a wider center 74 and thinnerlateral positions, 76, 78 as best seen in FIG. 3. The spacing betweenthe slats 70 is designed to permit the passage of contaminated waterfrom the aquarium tank through the grill while preventing passage offish through the grill. The grill substantially forms the entire heightof the wall 66. At the upper edge is a border strip 80 for fittingbeneath the cover member to retain the grill in place, as willhereinafter be described. The border strip 80 includes lateral retainingarms 82, 84 which rest on the shoulders 44, 46 of the side edge walls40, 42.

Laterally projecting on either side of the convex wall 66, are a pair ofretaining wall sections 86, 88 which define shoulders for fitting behindthe side edge retaining walls 40, 42 extending in front of the forwardwall 38. With the grill member 16 in place, as shown in FIG. 3, thegrill member 16 defines with the concave forward wall 38 an oval shapedchamber 90 serving as the inlet chamber for receiving contaminated waterfrom the aquarium tank. The height of the grill member 16 substantiallycorresponds to the height of the forward concave wall 38. The lower endof the grill member 16 fits on a forward projecting ledge of the basewall 28 so as to define a substantially closed bottom.

The L-shaped member 14 comprises a substantially flat circularperforated platform wall 92 with downwardly projecting feet 94. Theperforations 96 are grouped into sectors which are separated by solidpath strips 98 for support. A forward cutout portion 101 formed on theplatform 92 accommodates the inwardly projecting curved forward wall 38.The platform 92 includes perforations 96 which are sized so as to permitflow through of the water without passage therethrough of filtrationmaterial retained thereabove.

The platform 92 fits onto the base wall 28 of the container and isspaced thereabove by means of the feet 94 so as to define between theplatform and the base wall 28 a clear water chamber 100. Above theplatform 92, there is defined a filtration chamber in which appropriatefiltration material is placed. The filtration material is such that itremains within the container and cannot pass through the perforations.

Upwardly extending from the rear of the platform 92 is a convexpartition wall 104 having a pair of forwardly projecting, upwardlyflared side walls 106, 108. The upper ends of the side walls arerearwardly tapered as shown at 106a and 108a. With the platform 92sitting above the base wall 28, the side walls 106, 108 fit into thechannels 54, 56 and are securely retained therein. The space between therearward portion of the peripheral wall of the container and thepartition wall 104 defines an oval air lift chamber 110. As best seen inFIG. 5, the partition wall 104 substantially extends above the height ofthe container wall 24.

As best seen in FIG. 1, a depressed compartment 112 is formed beneaththe base wall 28 and extends into the neck portion 30. Mating with thecompartment 112 there is provided a projecting instep portion 114between the platform wall 92 and the partition wall 104 of the L-shapedinsert member 14. The instep 114 includes a pair of opposingsubstantially triangular side walls 116, 118, and a sloping forward wall120. As best seen in FIG. 5, the instep compartment 122 mates with thedepressed compartment 112 to define a chamber 124 for receiving an airdiffuser 126 therein. With the air diffuser positioned within thechamber, at least a substantial portion of the air diffuser 126 will bebeneath the platform wall 92, for a purpose to be hereinafter described.A downwardly projecting shoulder member 128 formed internally of theinstep portion serves as a locking member to retain the air diffuser 126in place.

The air diffuser 126 is connected at the distal end of a tubing 130 aspart of the air tube member 20. A coupling nozzle 132 on the airdiffuser couples to one end of the tube, and a coupling 134 can beprovided at the other end of the tube 130 for connection to an airsupply, such as a pump.

As best seen in FIG. 5, the tubing 130 fits through the spout 48 byentering the mouth 52 of the spout 48 and passing along the rear wall 50thereof so as to enter into the air lift chamber 110 defined between thepartition wall 104 and the rear of the peripheral wall 24 of thecontainer. The air tubing 130 extends downward to the base of the airlift chamber 110 until the air diffuser 126 is captured beneath theshoulder member 128 and restrained in place.

The cover member 18 includes a substantially cylindrical outer wall 136with a top wall 138 downwardly sloping toward the front direction. Anoutwardly extending radial flange 140 surrounds the bottom periphery ofthe outer wall 136 and terminates in a downwardly depending skirtportion 142. A pair of opposing socket openings 144, 148 are providedfor receiving the locking tabs 58, 60.

At the rear of the peripheral edge of the cover there is provided aninwardly directed notch 150 for mating with the mouth 52 of the spout 48so as to provide a composite opening for receiving the air tubing 130. Apair of outwardly projecting channels 152, 154, which are upwardlynarrowing mate with the channels 54, 56 in container 12 and receive therearwardly tapered ends of the side walls 106, 108 of L-shaped member14.

At the upper rear edge of the cover member is an oval shaped mouth 156having an upwardly extending peripheral lip portion 158. The shape ofthe mouth 156 is aligned with the oval shaped opening of the air liftchamber 110 defined between the partition wall 104 and the rear ofperipheral outer wall 24 of the container 12.

The cover member 18 when placed in position, serves to lock together thevarious assembled parts of the filter, as best seen in FIGS. 2 and 5.Specifically, the forward skirt portion 142 fits around the grillportion and overlies its upper ledge 80 to retain the grill locked inplace. The forward lip 158 of the mouth 156 serves as a shoulderabutting against the upper distal edge of the partition wall 104.

Accordingly, with the cover 18 secured on to the container, all of theassembled parts are locked in place and a unitary filter assembly isprovided. Furthermore, with the air tube initially positioned in placeprior to the closing of the cover member, the air tube likewise getslocked in place by means of the shoulder member 128 holding the airdiffuser down. In this way, the air tube 130 can be used as a handle forlifting up and removing the filter assembly, or for inserting it ormanipulating it in the aquarium tank. All of the parts will be heldsecurely together even though the filter is lifted up by the air tube.

It should further be appreciated that in order to clean the assembly,all that is necessary is to remove the cover and disassemble the variousmembers. Once disassembled, the various wall sections defining the inletchamber, the clear water chamber, and the air lift chamber, areseparated. These chambers not being actually formed as compartmentsdisassemble into individual wall sections which can be easily cleaned asseparate walls.

In the prior art filters, closed containers were provided for thevarious chambers. Brushes were therefore required to clean the narrowcrevices of the closed container, making it difficult to clean all thecrevices. In the absence of such closed compartments in the presentfilter assembly, it is easy to clean the separate walls without thenecessity of inserting narrow brushes, and thereby the filter can beadequately cleaned of all contaminating material.

In operation, the filter is assembled and proper filtration materialplaced in the filtration compartment above the platform 92. With thefilter placed at the bottom of the aquarium, gravel can be situatedabove the pedestal wall 32 so as to hold the filter securely in place.It should be noted, that the pedestal wall is integral with thecontainer so that when lifting the filter the pedestal will not falloff.

Contaminated water can flow through the grill into the inlet compartment90. The water can then flow over the top of the forward wall 38 sincethe sloping cover is spaced above the forward wall 36. The water willflow into the filtration compartment above the platform 92 where thewater will be filtered by the filtration material.

In order to keep the filtration material spaced from the cover 18 andprovide a flow chamber 160 for the contaminated water from the inletcompartment 90 to the filtration compartment 162, a retainer member 22is utilized. The retainer member 22 comprises a center hub 164 held bysupport struts 170 attached to a retainer wall 168. A prong 172 dependsfrom the top wall 138 for entry into the hole 166. Laterally projectingribs 174, 176, 178 are received in correspondingly provided slots inhole 166. By making the ribs varying in size, e.g. rib 174 larger thenthe others, and the receiving slots correspondingly sized, a keyedarrangement can be provided to mate the retainer member 22 onto theprong 172.

The water which passes through the flow chamber 160 beneath the covertop wall 138 flows through the filtration material in the filtrationcompartment 162. The now filtered water can pass downward through theperforations 96 in the platform wall 92 and flow into the clear waterchamber 100. As air is sent into the air lift chamber 110 through theair diffuser 126, the air will flow into the receiving compartmentdefined by the depressed portion beneath the clear water chamber. Theair will therefore flow upwardly into the air lift chamber. As the airflows upwardly, it causes a suction whereby the clear water will bepulled from the clear water chamber 100 into the air lift chamber 110and be drawn upwardly along with the air. This clear water will beaerated as it flows upwards through the air lift chamber. The water willthen flow out of the mouth 156 in the cover and back into the aquariumtank.

It should be appreciated that with the present construction there isprovided an aquarium filter which does not have separate pre-formedchambers. As a result, the air lift chamber is actually a compositeformed of separate walls which are merged adjacent to each other todefine the chamber.

Because of the lack of a separate pre-formed air lift chamber, when thefiltration material is inserted into the filtration compartment, it isnot necessary to wrap the filtration material around any areas blockedby tubes, compartments, or separate closed off areas. Similarly, sincethere are no closed pre-formed compartments, cleaning is easily achievedsimply by opening the cover and dumping out the filtering materials. Allparts are exposed and can be easily removed for cleaning.

The entire filter can be lifted by means of grasping the air linetubing. All parts are locked in place and lifting of the tubing will notcause disassembly of the filter. The platform is locked in place by thecover pressing down on the partition wall 104. The platform 92 in turnlocks the air diffuser in place and thereby retains the air tubingpermitting its use as a handle.

The platform 92 can be made with a very small perforation whereby finegrain carbon can be utilized as the filtration material which is muchmore efficient than courser carbons which are normally used.

The front grill being removable permits interchangeability of the sizeof the grill. In this manner, the size of the grill can be adjusted toaccommodate the various fish sizes in the aquarium tank. A baby savergrill can be provided for the use of the aquarium filter with tiny fish.

The air diffuser itself sits below the platform level providing maximumlift height for the air to flow without the need of additionalextensions. This adds additional force to the flow of the air, upwardlyincreasing the suction and permitting a greater flow through of thefiltered water. The air diffuser furthermore does not block or narrowthe air lift passageway as in prior art filters, and thereby permits agreater flow of water upwardly through the air lift chamber.

The air line tube itself comes out of the filter at approximately coverlevel as opposed to the prior art where it comes out of the top of thefilter.

The inlet chamber and the air lift chamber are compositely assembled,elliptically shaped compartments. Furthermore, the cylindrical shape ofthe filter itself avoids planar surfaces, which occur in prior artsquare and triangular filters. Accordingly, fish cannot get trappedbetween the walls of the filter and the aquarium tank walls.

Although the filter has been described as being circular, it should beappreciated that other shapes could be formed for the filter, such aselliptical, triangular, and others, and still obtain many of the uniquebenefits of this invention.

The pedestal portion being integral with the container prevents thefalling off of the pedestal as the filter is pulled upwardly by means ofthe air tube. The shape of the receiving chamber for the air diffuserincludes a forwardly sloped front end similar to the shape of anarrowhead. This permits directing the air from the air diffuser towardthe clear water chamber so as to provide greater suction of the clearwater into the air lift chamber. Also, it prevents obstruction of theflow of air.

There has been described heretofore the best embodiment of the inventionpresently contemplated. However, it is to be understood that variouschanges and modifications may be made thereto without departing from thespirit of the invention.

I claim:
 1. An aquarium filter for an aquarium tank, said filtercomprising in combination:a container having a forward wall, a grillmember coupled in opposition to said forward wall to define therewith aninlet chamber for receiving contaminated water from the aquarium, aremovable insert member having a perforated platform wall and anupstanding partition wall, said platform wall spacedly sitting onto thebottom of said container and defining with said container a filterchamber above said platform wall and a clear water chamber beneath saidplatform wall, said partition wall mating in opposition to a rearperipheral wall of said container and defining therewith an air liftchamber, and a removable cover member for mounting onto said containerand including a mouth aligned with said air lift chamber, wherebycontaminated water from said inlet chamber can flow over said forwardwall and into said filter chamber where said contaminated water issubstantially decontaminated before passing through said perforatedplatform to said clear water chamber for egress through said air liftchamber and out of said mouth back into the aquarium, and furthercomprising a depression formed into the bottom of the container withinsaid clear water chamber, and a protruding instep portion at thejunction between said platform wall and said partition wall for matingwith said depression to define a receiving chamber for receiving an airdiffuser, whereby at least a portion of the air diffuser is positionedbelow said platform wall to effectively extend the depth of the air liftchamber below the air water chamber, placing the air diffuser out of theair lift chamber so as not to block the air lift chamber and directingthe air into the space under said instep to provide greater clean waterflow into the air lift chamber.
 2. An aquarium filter as in claim 1,wherein the forward portion of said air diffuser receiving chambercomprises means to direct air flow from the air diffuser to said airlift chamber.
 3. An aquarium filter as in claim 1, and comprising apedestal depending from said container, an integral hollow neck portioninterconnecting said container with said pedestal, said hollow neckportion being in flow communication with said air lift chamber toeffectively increase the depth of said air lift chamber below the clearwater chamber, and wherein said depression is formed into said neckportion.
 4. An aquarium filter as in claim 3, wherein said container,said neck portion and said pedestal are integral and form unitarystructure, and said air diffuser extends into said neck portion.